Efficient estimation of sensory thresholds

Laboratory computers permit detection and discrimination thresholds to be measured rapidly, efficiently, and accurately. In this paper, the general natures of psychometric functions and of thresholds are reviewed, and various methods for estimating sensory thresholds are summarized. The most efficient method, in principle, using maximum-likelihood threshold estimations, is examined in detail. Four techniques are discussed that minimize the reported problems found with the maximum-likelihood method. A package of FORTRAN subroutines, ML-TEST, which implements the maximum-likelihood method, is described. These subroutines are available on request from the author.     

The commodore 64 and an interface system for controlling operant chambers

This article describes the interfacing of a Commodore 64 computer with an operant chamber. Advantages of the Commodore 64 over the VIC-20 as a controller are listed, and a sample program using dual response levers is given.     

Utilization of base-rate information during feeling-of-knowing judgments.

We examined whether subjects use base-rate information about item difficulty when making feeling-of-knowing judgments for items they failed to recall. First, the subjects attempted to recall the answers to general-information questions. Then, for those items they recalled incorrectly, half of the subjects received information about the normative probability of recall of each item while judging their feeling of knowing. The other subjects made their feeling-of-knowing judgments without receiving any base-rate information. Finally, all subjects had a forced-choice recognition test on those items to validate the accuracy of their feeling-of-knowing judgments. Relative to the no-base-rate information group, the base-rate group had lower feelings of knowing for normatively difficult items and higher feelings of knowing for normatively easier items. Subjects who had received base-rate information during the judgment state had greater feeling-of-knowing accuracy than subjects who did not receive base-rate information. However, even the predictions from subjects who received base-rate information were not significantly more accurate for predicting subsequent recognition than were the predictions derived from normative information alone.     

The Effects of Belief Systems on the Job-Related Satisfaction of Managers and Subordinates

The research reported here examined the effect of personal belief systems of managers and their subordinates on their interrelationships as measured by several job-related satisfaction variables. Results from a sample of 175 manager-subordinate dyads demonstrate that the belief system construct may significantly affect job-related satisfaction as well as the quality and outcomes of manager-subordinate relationships. This research also suggests that socially oriented managers are positively associated with higher levels of subordinate satisfaction.     

Assessing outcome in smoking cessation studies.

Outcome measures for smoking cessation are reviewed and evaluated, including 3 self-report measures and 3 biochemical validation measures. Point prevalence reflects the percentage of participants taking action, prolonged abstinence reflects those in the maintenance stage, and continuous abstinence reflects those who progress from action to maintenance without lapsing or relapsing. Biochemical assessments are primarily measures of point prevalence abstinence. The desirability of biochemical validation is a particularly controversial and critical issue. Three factors affect the accuracy of self-report: Type of Population, Type of Intervention, and Demand Characteristics. False-negative rates are generally low. Three broad issues impact on decisions to use biochemical validation: (a) alternative explanations for false positives, (b) refusal rate problems, and (c) the effect of inaccuracy on intervention assessment.     

Factor analysis for clustered observations

Classical factor analysis assumes a random sample of vectors of observations. For clustered vectors of observations, such as data for students from colleges, or individuals within households, it may be necessary to consider different within-group and between-group factor structures. Such a two-level model for factor analysis is defined, and formulas for a scoring algorithm for estimation with this model are derived. A simple noniterative method based on a decomposition of the total sums of squares and crossproducts is discussed. This method provides a suitable starting solution for the iterative algorithm, but it is also a very good approximation to the maximum likelihood solution. Extensions for higher levels of nesting are indicated. With judicious application of quasi-Newton methods, the amount of computation involved in the scoring algorithm is moderate even for complex problems; in particular, no inversion of matrices with large dimensions is involved. The methods are illustrated on two examples.Suggestions and corrections of three anonymous referees and of an Associate Editor are acknowledged. Discussions with Bob Jennrich on computational aspects were very helpful. Most of research leading to this paper was carried out while the first author was a visiting associate professor at the University of California, Los Angeles.     

Importance of the kind of cue for judgments of learning (JOL) and the delayed-JOL effect

The delayed-JOL effect is the finding in which judgments of learning (JOLs) are more accurate at predicting eventual recall when they are made a short time after study rather than immediately after study. The present research replicated this effect and found that the kind of cue that is used for JOLs is critical. In particular, following the study of stimulus-response paired associates, there is an extremely robust delayed-JOL effect when the cue for JOLs is the stimulus alone (every one of 45 subjects showed the effect); however, there is little, if any, delayed-JOL effect when the cue for JOLs is the stimulus-response pair. This finding has important implications for education: To have the greatest accuracy at predicting eventual recall, a person should make JOLs not immediately after study but, instead, shortly after study (i.e., delayed JOLs) with the cue for JOLs being the stimulus alone. The theoretical mechanisms for the delayed-JOL effect are currently unknown, but some speculations are offered.